To maximize the breathing I'd strongly recommend a K&N panel filter. Ideally the restrictive resonator trumpet and oval plate it attaches to in the front of the airbox need removing too. If you check the bore of the trumpet you can see why Will give a pleasant induction growl under load too then
A new filter is just as good as a K&N. It will over time get clogged faster that is all. No issues with a flap type AFM.
Also the removal of the airbox velstack ( not mentioned in the previous dyno measurement) will help to super inflate readings on another dyno of a different make and ambients. In my opinion it would be wise to rebaseline the vehicle as it was from the last dyno at this new facility then carry out adjustments, then test again. Saves blaming shops when they may have done a good job from the start.
Supersprint/VW exhaust fitted..apparently noisy?? My car went into the garage yesterday to have the custom stainless system removed and the Supersprint 2" two box system with VW standard front silencer fitted. The car also needed a driveshaft oil seal and as the garage were sent the wrong one by Euro Car Parts, it had to spend overnight in the garage whilst they wait for the proper seal to be delivered this morning!! I'm off to pick it up today, but spoke to them yesterday on the phone and they reckon I won't be happy with the noise levels on the Supersprint/VW system which they have already fitted??? Will be really hacked off if it is noisy!! I have read that Supersprint are amongst the quietest and most subtle of the aftermarket exhausts, so I can't believe it will be noisy. Guess I will have a better idea when I pick the car up! I have also read on here that if the ignition or cam timing is out then the exhaust note/noise level can be significantly affected? Is this correct. The engine just doesn't sound sweet at all? I am sure from what others have said on here that my cam timing is out (see previous posts in this thread) and my car is off to Stealth next Thursday to be properly set up. The horrible fuelling issue (violent misfire) seems to have reared it's ugly head again (although it is intermittant) and this seemed cured when the the car came back from it's Rolling Road tune at A B Garage a few weeks ago?? I haven't used the car at all for two weeks but drove it to the garage yesterday and the misfiring was pretty awful till the car warmed up. Something's not right??? I am a bit worried about driving the 150 or so miles to Stealth with my car in this state...but I guess it has to be done[:^(][:^(][:^(] Any ideas?? Cheers Paul
Well a quick update...got my car back from the garage this afternoon and the Supersprint exhaust is FANTASTIC!! Really don't know what the garage were on about??? Anyway the Supersprint is lovely and quiet but with a lovely note under full throttle, looks great too!! Just what I was after! Roll on Stealth next week!! Cheers Paul
Some good news at last. Could the worm finally be turning for Alpenweiss2 at last? Now the grim news is, who is going to get all the bad luck now?
Hi Danster...yes I really hope the worm has turned now. Hopefully Stealth will get it set up nice and then I can enjoy my investment!! Cheers Paul
What a runaround! Never was a mildly tuned 8v GTI's rolling road session so anticipated! Not too unlike yourself AlpenWeiss2 , I've a Mk2 PB GTI here , with 4 branch manifold (TSR) , GS2H Cam and Vernier pulley , P+P head and reworked valves.... and I'm not overly happy with the performance . Pulls clean and clear , ticks over smooth , but just seems not a lot better than a good standard one . My problem is I did it all myself though....
131.7bhp!! Arrived down in Kent a couple of hours ago after travelling from North Wales and called in at Stealth Racing in Warwickshire on the way to get my car finally sorted out!! Had a good chat with Vince when I got there and explained that I thought the cam timing was out. He did a baseline dyno run and it showed 122BHP at the flywheel on the Stealth rollers. He then removed the rocker cover to check the camshaft timing. He reckoned that the marks on the vernier were not correct, but the cam timing was okay, so the belt didn't need to be removed. He did a few power runs and adjustments and also removed the trumpet thingy from the airbox. After several adjustments the car ran with 131.7BHP at the flywheel and 108.4 BHP at the wheels I pretty happy with that, although he said he had hoped to get a few more BHP. He reckons the engine will loosen up with more miles and I should see another 4-5 BHP. I was very happy with the service at Stealth and the charge was very reasonable. I mentioned to Vince that the oil temperature had been edging up to 112 degrees on a run. After the tune up at Stealth it is still running between 106-110 degrees at motorway speeds. Unfortunately the car still has a very intermittant misfire? It happened three or four times on the drive from Stealth to Kent and lasts about a second or so and also the rev counter needle flickers?? I will speak to Vince to see what he thinks. The car has a new VW distributor, new plugs, plug leads and also a reconditioned AFM. Is it likely to be fuelling or possible issues with the fuel pump? Any ideas guys? The car feels great to drive, especially at motorway speeds! It flys above 4500RPM and acceleration is instant It pulls like a train. Just the high oil temperature and occassional misfire which is worrying. Cheers Alpenweiss2
good result, i would try a different coil if you can, they seem to be getting to an age where they are becoming a commom problem. whats the torque figure?
hmm yes, ecu relay would be on the list as well as the pump relay. if rev counter is flickering that suggests its not an issue with the coil or spark after that, but how the ecu is triggering it. I'd be looking closely at the wiring to the distributor and general ecu wiring. also was the new dizzy a quality bosch item or an ebay cheapie?
Progress at last! Try swapping bits over to the other car to see if you can diagnose what's causing the misfire. Coil and ignition amp would be good to check, but make sure the contacts in the hall sender plug aren't slipping back inside the plug, and that the spade terminals on the coil are good and tight. I think it's more likely electrical than fuelling, otherwise it wouldn't be 'flying above 4500 rpm'
Agreed! Digifant fuelling problems don't tend to be intermittent and would have shown up during the heavy loads encountered on the RR. The fuel pump would be noisy if it or the lift pump were on the way out. Nothing else in the system plays up really.. Most likely to be dizzy/coil/hall sender related
I have spoken to Vince and he has suggested a few things that may be causing the misfire, so I will be checking through the list of things he has given me:- 1.) Loose plug leads 2.) Loose or missing earth lead on the rocker cover rear right corner (affecting instruments) 3.) Dodgy relay (3rd from left on upper row in the fuse box). He also said that excessive engine movement could give similar symptoms to what feels like a misfire. He suggested a possible uprated front engine mount, such as Vibratechnics as the engine is now putting out 132BHP. He suggested I try lifting off and pushing on the throttle in third gear at roughly 30mph to see if this movement is noticable. I have replaced most of the electrical/ignition stuff with new plugs, new VAG exchange distributor, Bosch leads, VAG plugs. I also swapped the coil over for a spare one I had from another 1991 Digifant gti. I guess it will be one of those niggly problems to sort. It never had the issue before the rebuild, so it must be something loose. As for the car the vernier is set up showing about 10 degrees retarded but that is not the actual setting according to Vince due to the vernier marks not being correct I don't really understand the cam timing but the car feels great to drive..so that's the main thing. The torque output is 132.3 lbft, which is a decent hike over the standard 114lbft. The car drives really urgently now with a little more induction roar as the trumpet has been removed. The power comes in further up the rev range than a standard gti 8 valve so it probably drives a bit more like a 16 valve now? I forgot to mention to Vince on the phone that the car is still running with higher oil temperatures, so if anyone has thoughts on that I'd be interested to hear. At a steady 80mph oil temp on the MFA is between 108-110 degrees. I will post up the power graphs once I get home from Kent. Cheers Alpenweiss2
